Diphenolic acid (DPA), produced from cellulose-derived levulinic acid (LA), can potentially displace bisphenol A as a structural analogue in the preparation of polybenzoxazines, aromatic polyesters and polycarbonates.We present the use of water-soluble sulfonated hyperbranched poly(arylene oxindole)s in combination with ultrafiltration as a conceptually novel approach for the catalytic production of LA from cellulose. LA can be subsequently converted into DPA by a thiol-promoted acid-catalyzed condensation with phenol. For this reaction, we will discuss a mechanistic study of the kinetic and regiochemical effects that alkyl- and benzyl-substituted thiols have on the observed reaction rates and product selectivity. Taft linear free energy relationships show that steric effects play a predominant role in determining the condensation rate, while kinetic effects alter the regioselectivity towards the desired p,p'-DPA isomer. The hitherto overlooked catalytic isomerization of p,p'-DPA will be demonstrated by condensation reactions with both m-cresol and 13C-labeled phenol supported by DFT calculations.

From cellulose to a potential substitute for bisphenol A: The design, application, and mechanistic understanding of a hyperbranched catalytic approach

245th National Meeting (2013)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.